This invention relates to the monitoring of a process for the partial oxidation of carbon-containing fuel, particularly coal, with an oxygen-containing gas in a reactor under high pressures and temperatures. In its preferred form, it relates to a process for monitoring a gasifier in which the product gas and fly ash formed is removed at the top of the gasifier and slag is removed at the bottom of the reactor.
Many carbon-containing fuels are of mineral origin, and often contain, in addition to carbon and hydrogen, varying quantities or inorganic incombustible material. The latter material is a by-product of the process of oxidation, and, depending on characteristics such as density and size of the particular particle, and the reactor configuration and conditions, may undergo a rough separation in the reactor into particles called "flyash" (lighter) and "slag" (denser). The flyash particles may be removed overhead with the product synthesis gas through a zone or conduit where the gas and particles are quenched (quench zone), while the denser materials may collect as a molten slag in the hearth of the reactor and are discharged downward through an outlet or orifice in the hearth into a water bath. In some gasification processes, product gas, slag, and flyash are removed together from one outlet, but undergo a similar separation.
A real concern in such processes is that the flyash and/or slag may collect and solidify at the outlet of the gasifier or in the area within the quench zone near the outlet to such an extent that the flow of the gas is undesirably impeded or blocked. Blockage of the gasifier outlet or quench zone represents a potentially catastrophic situation and requires shut-down of the process, an obviously unsatisfactory circumstance. The invention is directed to overcoming this problem.